11.1. Loops (Revision #2)

A loop is a block of code that iterates ¹ a list of commands as long as the loop control condition is true.

for loops

for arg in [list]

This is the basic looping construct. It differs significantly from its C counterpart.

for arg in [list]
do

command(s)...
done

During each pass through the loop, arg takes on the value of each successive variable in the list.

for arg in "$var1" "$var2" "$var3" ... "$varN"  
# In pass 1 of the loop, arg = $var1        
# In pass 2 of the loop, arg = $var2        
# In pass 3 of the loop, arg = $var3        
# ...
# In pass N of the loop, arg = $varN

# Arguments in [list] quoted to prevent possible word splitting.

The argument list may contain wild cards.

If do is on same line as for, there needs to be a semicolon after list.

for arg in [list] ; do

Example 11-1. Simple for loops